1:00 ejection & Short stroking ?

[georgeib]

In your experience what causes the premature wear of the bulb on the end of the gas tube?”

Not @markm, but the answer to your question is slight misalignment between the gas key and tube. I've had to replace a tube on a mid length before and it turns out the gas block had come loose. Ultimately, I imagine with enough rounds even a perfectly aligned gas tube will wear down.

[tech3]

If your problem just started recently and there was no problems with the buffer weight before
I would for sure check for gas leaks before changing buffer weight I shoot a lot of IMI 55 gn. ammo
and it is a hot load and has 27.5 gn. of powder in it
That is where I would start.

[markm]

In your experience what causes the premature wear of the bulb on the end of the gas tube?”

There HAD TO have been a batch of shitty tubes. In middy specifically. There was another guy here who had similar experiences. I first thought the gas key had roughness inside and was wearing out the tube, but that wasn't it.

[HKGuns]

I use one of these. Mine are all good so far.......However, it it weren't a thing, this wouldn't exist.

Gas Tube Gauge

[markm]

Both of my tubes failed on relatively low round counts. I don't know if these tubes didn't get some sort of proper heat treatment or something, but they were worn down to the regular diameter of the tube and puking fouling under the handguard.

[JoeBobJoe]

This would be my thought as well. My 13” mid barrel with 0.076 gas port has a violent bolt speed with a regular carbine spring and buffer.

Issues I thought were short strokes were from excessive bolt speed.

After moving to A5 lower with a5h2 buffer it’s the smoothest shooting rifle I own.


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I tried a standard 3 oz buffer & it started ejecting at 3 o'clock but still only about3 feet. I recorded it in slow motion & it's bouncing the brass off the brass deflector but still lazy ejection.
My main concern is it's not 100 % reliable with GI aluminum mags. I get 2 to 3 short stroke stoppages (round is under bolt half way) per mag.
I'm using D&H & Okay mags. PMags seem GTG.
It's a 16 inch factory Spikes ST15.
I think it's under gased. The new round is stuck under the bolt, as if the bolt didn't go back far enough to pick up next round, but the bolt locks back on empty mag every time. I can't figure it out.
Thanks for the help.

[Inkslinger]

How old are the springs in the mags causing problems? I imagine if it’s overgassed (which being Spikes it probably is) and you have magazine springs that are worn out, you could end up with what you just described. It’s not the bolt going back far enough, it’s the magazine springs not having enough force to get the round up quick enough for the bolt to pick it up.

[JoeBobJoe]

If your problem just started recently and there was no problems with the buffer weight before
I would for sure check for gas leaks before changing buffer weight I shoot a lot of IMI 55 gn. ammo
and it is a hot load and has 27.5 gn. of powder in it
That is where I would start.

It's only with GI mags, I can't remember if I only ran P mags in it & no aluminum mags, because I do like mixing GI & P mags for training. It runs 100 percent with P mags but still a weak ejection. I'm getting 3 stoppages per GI ma, the Bolt over the new round like a short stroke, but bolt locks open.
I never noticed it beforehand. Like I said it was ejecting 1:30 with a 4 oz buffer now 3:00 with a 3 oz buffer so that is strange.
But I'm thinking of opening the gas port, via drill bit lol. I'm thinking about it. It's that frustrating. It's a factory gun, I never had a stoppage with a "home build" I been lucky I guess. The gun was my son's he wanted to sell it I bought it

[markm]

I think it's under gased.

It sounds like it, but under gassing would be almost unheard of with most guns being over gassed. Any signs of leakage around the gas block or gas key?

Any other ammo you can try?

[JoeBobJoe]

Both of my tubes failed on relatively low round counts. I don't know if these tubes didn't get some sort of proper heat treatment or something, but they were worn down to the regular diameter of the tube and puking fouling under the handguard.

I don't see any signs of leaking gas. I even put paper around gas tube where it goes into gas block, the paper doesn't move or get tore up. The Carrier & upper are clean looking, I ran another carrier & ran that carrier in other gun. I pulled my gas block (pinned from factory)had perfect alignment. I'm thinking about opening the gas port, since I got it apart. Crazy, but It's not reliable, I value reliability over everything. What's your thoughts on opening gas port a hair. My son has pinned front sights & gas blocks so I got some knowledge to help me.